There are areas in which the size of the local bird populations can present problems. At airports, the presence of a large bird population, especially seagulls, can present safety problems because it increases the likelihood that a bird(s) will be sucked into a jet engine and cause engine failure. At cattle feed lots, where bird populations can reach three million or more per day, the birds can cause multiple problems, such as feed consumption, defecation and the spreading of diseases, such as salmonella. In addition, large populations of birds such as pigeons, starlings, crows, red wing blackbirds and house sparrows can cause problems in parks, cities and neighborhoods.
Varied approaches have been tried in the past to control such populations. Obviously, the drugging or poisoning of the birds is not acceptable because of the risk to other animals, including humans, and the accumulation of dead birds. Attempts have been made to drive the birds away with noise or light or other means. However, none of these approaches have been particularly successful.
Therefore a need exists for a method of controlling bird populations, especially in areas where they are pests.
There also is a need for a safe and effective method of controlling the reproductivity of birds without harming the birds or endangering other animals, including humans. Bird populations can be controlled more effectively if they are allowed to mate, lay eggs and occupy part of their life cycle in an attempt to hatch eggs.